Turbomachines such as e.g. gas turbines are characterized in that they consist of multi-stage compressor and turbine components. Here, a compressor or turbine stage includes a stationary stator blade row and a rotating rotor blade row. The stator blade and rotor blade row consists of a multiplicity of individual blades. Therefore, an overall machine includes several hundred stator and rotor blades. When the machine is in operation, these blades are subject to high mechanical, aerodynamic and thermal loads.
These loads can lead to unwanted damage of the blades. The specific problem existing here has initially only little damage at a single blade being able ultimately to lead to total loss during the course of the further operation of the machine. This damage progression constitutes a known phenomenon and can develop from minimal initial damage to total loss over a period of time of a few minutes to days. Therefore, the pressing problem lies in identifying the small initial damage, which may have multifaceted causes and characteristics, during the operation of the machine and being able to derive a warning. The repair outlay for removing little initial damage is very much smaller than a total loss of the machine, in which all blades and, in part, also further components such as burner, filter, pressure sensors etc. need to be replaced.